dojo/text plugin may load resources twice

[ben hockey]

if the loader is in async mode it's possible that two requests for the same dojo/text! resource may occur before one of them is fulfilled. in this case, on the 2nd request, the cache will be empty and the plugin will try to load the resource. this will result in the resource being loaded twice.

from attached example (in async mode):

require([
        'dijit/form/DateTextBox',
        'dijit/form/FilteringSelect'
], function () {
        console.log('loaded');
});

the above example results in dijit/form/templates/DropDownBox.html being loaded twice.

[Rawld Gill]

Fixed in [25933]; thanks neonstalwart for the nice test case.